Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 500

DI-45

Rear Differential (T-type)

DIFFERENTIALS

12) When the bearing preload is out of the speci-

fied range, select the preload adjusting washer and

spacer from the following table in order to make it

within the specified range.

13) Remove the self-locking nut while securing the

companion flange with ST.

ST 18633AA000 WRENCH COMPL

14) Extract the companion flange with a puller.

15) Using the ST, install the oil seal.
NOTE:

• Use a new oil seal.

• Press-fit until the oil seal end comes 1 mm (0.04

in) inward from end of carrier.

• Apply differential gear oil to the oil seal lips.

ST 498447120

INSTALLER

16) Press-fit the companion flange with ST1, ST2,

and ST3.

ST1 899874100

INSTALLER

ST2 399780104

WEIGHT

ST3 498937110

HOLDER DRIVE PINION

NOTE:

Be careful not to damage the bearing.

Preload adjusting washer

Part No.

Thickness mm (in)

383705200

2.59 (0.1020)

383715200

2.57 (0.1012)

383725200

2.55 (0.1004)

383735200

2.53 (0.0996)

383745200

2.51 (0.0988)

383755200

2.49 (0.0980)

383765200

2.47 (0.0972)

383775200

2.45 (0.0965)

383785200

2.43 (0.0957)

383795200

2.41 (0.0949)

383805200

2.39 (0.0941)

383815200

2.37 (0.0933)

383825200

2.35 (0.0925)

383835200

2.33 (0.0917)

383845200

2.31 (0.0909)

Preload adjusting spacer

Part No.

Length mm (in)

31454AA130

52.2 (2.055)

31454AA140

52.4 (2.063)

31454AA150

52.6 (2.071)

31454AA160

52.8 (2.079)

31454AA170

53.0 (2.087)

31454AA180

53.2 (2.094)

DI-00091

ST

(A) Companion flange
(B) Puller

DI-00142

(B)

(A)

DI-00089

ST

ST3

ST1

ST2

ST2

DI-00323

DI-46

Rear Differential (T-type)

DIFFERENTIALS

17) Apply seal material on the drive pinion shaft

thread and new self-locking nut seat.
Seal material:

THREE BOND 1324 (Part No. 004403042) or

equivalent

18) Attach the new self-locking nut and use the ST

to fix the companion flange in place, then tighten

the self-locking nut.
Tightening torque:

181.5 N·m (18.5 kgf-m, 133.9 ft-lb)

ST 18633AA000 WRENCH COMPL

19) Check the initial torque or initial load.
Initial load:

24.1 — 38.6 N (2.5 — 3.9 kgf, 5.4 — 8.7 lbf)

Initial torque:

0.98 — 1.57 N·m (0.10 — 0.16 kgf-m, 0.72 —

1.16 ft-lb)

20) Install the driven gear to the differential case.
NOTE:

• Before installing bolts, apply seal material to bolt

threads.
Seal material:

THREE BOND 1324 (Part No. 004403042) or

equivalent

• Make sure there is no clearance between the dif-

ferential case and driven gear.

• Tighten opposing bolts in order.
Tightening torque:

103 N·m (10.5 kgf-m, 76.0 ft-lb)

21) Using the ST, press-fit the side bearing to the

differential case.

ST 398487700

DRIFT

22) Using the ST, press-fit the side bearing outer

race to the side retainer.
CAUTION:

Make sure that the bearing outer races and

cones are properly assembled.

ST 398417700

DRIFT

DI-00071

ST

DI-00715

DI-00481

DI-00068

DI-00095

ST

DI-00324

ST

DI-47

Rear Differential (T-type)

DIFFERENTIALS

23) Side retainer shim adjustment

(1) The hypoid driven gear backlash and side

bearing preload can be adjusted by the side re-

tainer shim thickness.

(2) Install the differential case assembly into dif-

ferential carrier in the reverse order of disas-

sembly.

NOTE:

Be careful not to hit the teeth of hypoid driven gear

against the differential carrier.

(3) Install the side retainer shim.

NOTE:

• Be careful not to mix up the side retainer shim

RH and LH.

• Replace broken or corroded side retainer shims

with a new part of the same thickness.

(4) During installation, align the arrow mark on

the differential carrier with the arrow mark on

the side retainer when installing the side retain-

er.

NOTE:

Be careful that side bearing outer race is not dam-

aged by the bearing roller.

(5) Tighten the side retainer bolts.

Tightening torque:

10.5 N·m (1.1 kgf-m, 7.7 ft-lb)

(6) Measure the hypoid driven gear to drive pin-

ion backlash. Set the magnet base on differen-

tial carrier. Align the contact point of dial gauge

with tooth face of hypoid driven gear, and move

hypoid driven gear while holding drive pinion

still. Read the value indicated on dial gauge. If

the backlash is outside the standard range, ad-

just the side retainer shim by the following

method.

Side retainer shim

Part No.

Thickness mm (in)

383475201

0.20 (0.0079)

383475202

0.25 (0.0098)

383475203

0.30 (0.0118)

383475204

0.40 (0.0157)

383475205

0.50 (0.0197)

DI-00065

(A) Arrow mark (on the side retainer)
(B) Arrow mark (on the differential carrier)

DI-00543

(B)

(A)

DI-00487

DI-48

Rear Differential (T-type)

DIFFERENTIALS

•

When backlash is less than 0.1 mm (0.004

in):

Reduce the thickness of shim on the back side

of the hypoid driven gear and increase the

thickness of shims on the teeth side of the hy-

poid driven gear.

•

When backlash exceeds 0.2 mm (0.008

in):

Increase the thickness of shim on the back side

of the hypoid driven gear and reduce the thick-

ness of shims on the teeth side of the hypoid

driven gear.

Backlash:

0.10 — 0.20 mm (0.004 — 0.008 in)

(7) Measure the total preload of the drive pin-

ion. If the total preload is not within specifica-

tion, adjust the thickness of side retainer shims,

increasing/reducing both shims by an even

amount on both sides.

Total preload:

26.5 — 53 N (2.7 — 5.4 kgf, 6.0 — 11.9 lbf)

24) Recheck the hypoid driven gear to drive pinion

backlash.
Backlash:

0.10 — 0.20 mm (0.004 — 0.008 in)

25) Check drive pinion and hypoid driven gears ro-

tate smoothly and make sure of the hypoid driven

gear runout on its back surface. If the runout on the

back side of the hypoid driven gear exceeds the

specification, check for any foreign material be-

tween the hypoid driven gear and differential case,

and for any deformation of the case or gear.
Hypoid driven gear back surface runout:

0.05 mm (0.002 in)

26) Checking and adjusting the tooth contact of hy-

poid driven gear

(1) Apply lead-free red dye evenly on the both

sides of three to four teeth of the hypoid driven

gear. Check the contact pattern after rotating

the hypoid driven gear several revolutions back

and forth until a definite contact pattern appears

on the hypoid driven gear.

(2) When the contact pattern is not correct, re-

adjust.

NOTE:

Be sure to wipe off the lead-free red dye completely

after the adjustment is completed.

• Correct tooth contact

Check item: Tooth contact pattern is slightly

shifted toward toe side under no-load rota-

tion. (When driving, it moves towards the

heel side.)

DI-00099

DI-00099

(A) Toe side
(B) Heel side

DI-00101

(A)

(B)

MT-01401